Hawkweeds (Genus Hieracium) in the Portland-Area How to Distinguish Between Those Darn (Mostly Yellow) Composites!

Hawkweeds (genus Hieracium) in the Portland-area How to distinguish between those darn (mostly yellow) composites!

Mandy Tu Plant Taxonomist & Herbarium Curator Hoyt Arboretum Portland Parks & Recreation Main Points for Today…

1. Brief overview of Asteraceae

2. The hawkweeds! (genus Hieracium) - Which ones are here (natives & exotics) and likely to see - Which ones should we be watching? - How to distinguish between them (features to look at)

3. Resources for identification

** Give you the tools…to correctly recognize, distinguish & identify hawkweeds!** Super-duper brief overview of Asteraceae/Compositae (sunflower family)

• Mostly herbs & shrubs • Many flowers per heads/capitulum, borne on a receptacle • Flowers with 5 (fused) petals

Olearia telmatica, New Zealand • Heads surrounded by “sepal-like” bracts called phyllaries

Ligulate flower What is the big deal with the hawkweeds (Hieracium)?

• Common name 'hawkweed’ (Latin hierax), originated from a folk tale that hawks ate different parts of the plant to improve their eyesight

• In PNW…a few natives, some exotics, some invasive exotics

Field of H. aurantiacum in B.C. (photo from bcinvasives.ca)

• Invades open areas, disturbed sites • Can form dense monocultures • Competes with and displaces natives in H. albiflorum, a common meadows, grasslands PNW understory native Characteristics of the genus Hieracium… (how to distinguish them from other Asteraceae?)

General characters: • Biennial or perennial herb, typically 10-120 cm tall, milky sap • Stem erect, branched or not, not thorny, often with hairs • Heads few to many, flowers typically 6-60 per head • Involucre cylindric to bell-shaped, phyllaries in 2-4 series • Ligulate (strap-like) flowers only – like dandelions • Corollas generally yellow, sometimes white or orange in color

H. albiflorum

H. umbellatum H. caespitosum H. lachenalii Characteristics of the genus Hieracium… (how to distinguish them from other Asteraceae?)

Specific characters: 1. Receptacle epaleate (no bristles or bracts/scales on the receptacle)

For comparison, if has paleae… Hypochaeris, Agoseris

H. umbellatum Hypochaeris glabra 1. Pappus of many simple bristles, minutely barbed, persistent in fruit

H. umbellatum

1. Fruit not compressed (cylindric in shape), not beaked For comparison, fruit compressed… Lactuca, Sonchus Lactuca sp. New PNW Flora: 22 Hieracium species (9 natives, 13 exotics) 4-county CWMA area, incl Gorge: 10 species (5 natives, 5 exotics) CWMA list has 13 exotic species For this presentation…include: Natives ODA CWMA Metro H. albiflorum white flowered (native) hawkweed H. umbellatum narrowleaf or (native?) umbellate hawkweed Exotics H. aurantiacum orange A A A hawkweed, king devil H. caespitosum meadow B A A hawkweed H. lachenalii English Not listed Watch A hawkweed H. murorum golden lungwort Not listed Watch A

H. pilosella mouse ear A A A hawkweed H. sabaudum European Not listed Needs A hawkweed investigation

H. x floribundum glaucous A A Not hawkweed listed How to distinguish between the Hieracium species…

Best identification resources…

Also… • Flora of North America (online) • Jepson Manual, CA Flora

Photos/Images: • Oregon Flora Project (photos) • Consortium of PNW Herbaria Brand new!! How to distinguish between the Hieracium species… (Based on new PNW flora) White flowers Start with, it is a Hieracium!! (Ligulate flowers, epaulate receptacle, simple pappus, Orange flowers cylindric fruits) H. albiflorum (native) White-flowered hawkweed Yellow flowers How to distinguish between the Hieracium species…

Start with, it is a Hieracium!! H. aurantiacum Orange flowers Orange hawkweed, king-devil hawkweed

• 3-16 heads, form dense flat- topped corymb • Heads clustered near top of stem • Last documented in PDX-area in Hieracium x stoloniflorum 1920s near Crown Point (forking hawkweed) • Others: Mt. Hood (Lolo Pass), • 2-3 heads Coast Range • Forked near middle of axis • None documented in OR! How to distinguish between the Hieracium species…

White flowers… H. albiflorum (native) Start with, it is a Hieracium!! (Ligulate flowers, epaulate Orange flowers… 3-16 heads, dense corymb…H. aurantiacum receptacle, simple pappus, cylindric fruits) Yellow Stolons/leafy runners flowers

Short, erect rhizomes How to distinguish between the Hieracium species…

Yellow Stolons/leafy runners Start with, it is a Hieracium!! flowers Hieracium pilosella • Mostly solitary heads Mouse-ear hawkweed • Thin, narrow leaves • Margins entire • 1 documented in Portland in 1960 • Others closest: Yamhill Oaks, Salem, Hood River How to distinguish between the Hieracium species…

Yellow Stolons/leafy runners Start with, it is a Hieracium!! flowers

• 6-80 heads

• Stems & leaves mostly glaucous Society BotanicalCT • Leaves long and narrow • Entire margins • None documented in Oregon! Hieracium x floribundum (H. lactucella x H. caespitosum) • Closest Tacoma area Glaucous hawkweed, yellow hawkweed How to distinguish between the Hieracium species…

Yellow Stolons/leafy runners and/or Start with, it is a Hieracium!! flowers short/erect rhizomes

H. caespitosum (meadow hawkweed) • 6-80 heads • Leaves with long, smooth hairs on both surfaces • Involucre with long, smooth, dark hairs • Leaves narrow and long, margins entire • 1 documented in 2017 in Estacada • All others higher elev or further east & north How to distinguish between the Hieracium species…

Short, erect rhizomes

H. murorum H. lachenalii

Distinguished by: • Leaf margins • +/- stem leaves • +/- petioles H. umbellatum (native?) H. sabaudum • Hair characteristics How to distinguish between the Hieracium species…

Yellow Start with, it is a Hieracium!! Short/erect rhizomes! flowers

H. umbellatum – native? (narrow-leaved hawkweed)

• Leaves long and narrow, toothed margins, sessile • Long hairs and stellate hairs on stems • Involucre with long hairs, few glands • PDX area: Hoyt Arboretum, Sauvie’s Island, Gorge How to distinguish between the Hieracium species…

Yellow Short/erect rhizomes! Start with, it is a Hieracium!!

flowers King Co. weeds Co. King

• Stem & basal leaves toothed, stem leaves sessile H. sabaudum • Long, white hairs on stem; peduncles with stellate & (European hawkweed) glandular hairs • Documented in 2017 near Estacada in Mt. Hood NF. Next closest in WA near North Bend (east of Seattle, higher elevs), more in B.C. How to distinguish between the Hieracium species…

Yellow Start with, it is a Hieracium!! Short/erect rhizomes! flowers

H. murorum (wall hawkweed)

• Toothed basal leaves • Leaves with petioles • Leaf bases cordate (with “tails”) • Several documented in PDX-area: Mt. Tabor, Council Crest, Hoyt Arboretum How to distinguish between the Hieracium species…

Yellow Start with, it is a Hieracium!! Short/erect rhizomes! flowers

H. lachenalii (common hawkweed)

• Toothed basal leaves • Leaves with petioles • Leaf bases cuneate • Documented at Hoyt Arboretum, Gorge and Camas, WA In Conclusion…

**Given you the tools to correctly recognize, distinguish & identify some hawkweeds!

• Super-brief overview of Asteraceae • Characteristics to identify the hawkweeds (genus Hieracium) • What characteristics to look for, to distinguish species. • Resources for identification

Become friendly Mandy Tu with your local Hoyt Arboretum florae! [email protected]